Painful hand swelling may be caused by physiological factors such as excessive hand activity and hot environment, or it may be caused by pathological reasons such as gout and infection. 1. Physiological factors: the hand belongs to one of the important organs of the human body, a lot of fine movements are completed through the operation of the hand, excessive strain on the hand may cause fatigue of the hand tendons, ligaments and other soft tissue parts, hand swelling, pain symptoms. In summer, due to the hot weather, the hand is exposed to strong sunlight for a long time, which may cause local vasodilatation, and the above symptoms may also occur. 2. Pathological causes: when gout occurs due to hyperuricemia, it may lead to the deposition of uric acid crystals in the joints of the hands, causing the body to have a metabolic reaction, resulting in the symptoms of swelling and pain in the hands. Infection of the hand will make the permeability of local blood vessels increase, and the contents of blood vessels free to the tissue interstitial reaction with the immune system, resulting in inflammatory manifestations of redness, swelling, heat and pain, such as purulent dactylitis, onychomycosis and so on. If the symptoms of hand swelling and pain are not relieved, or accompanied by other symptoms, you should go to the hospital in time to clarify the cause and then give targeted treatment.